Pharmaceutical products and associated packaging machines are typically subject to strict manufacturing guidelines. A variety of items, such as tablets, capsules, and the like, must be packaged to meet the minimum sterility requirements mandated by federal regulations. Items should be delivered and counted accurately such that the contents accurately reflect the claimed “count”. It has been the goal of many manufacturers to provide a machine that can minimize the cost associated with operating the machines and provide the greatest ability to inspect the product just before it enters the final container.
In the past, many packaging machines utilized intermittent motion, wherein the movement of containers would be stopped during filling. Recently, many packaging machinery builders have turned to rotary designs for their high-speed equipment. Rotary designs offer higher throughputs and require less floor space.
Conventional pill-filling machines have taken on many different configurations and a variety of delivery and counting methods but with very little inspection. Generally, pill-filling machines utilize some common elements. Most use a rotary slat conveyor, commonly known as a “slat” in the industry, to pick up tablets from a hopper and delivery them to a container. The container to be filled is moved into position and is held stationary while the slat fills the container. Tablets filling the container pass through an optical device, which counts or otherwise analyses the product. In all of these configurations the tablets are delivered one at a time and the bottle is stationary while being filled.
In the past, pill-filling machines used a variety of methods to achieve the desired count. In U.S. Pat. No. 3,139,713, which is incorporated herein by reference, Merrill loads a certain amount of slats in one direction and turns the whole slat at one time. Merrill picked up many tablets from the first location, but delivered to the second location, each individual tablet. In U.S. Pat. No. 4,674,259, which is incorporated herein by reference, Hills proposes a similar method.
Recently, in U.S. Pat. Nos. 6,799,413 and 6,401,429, which are both incorporated herein by reference, Aylward proposed a similar method but also disclosed means for delivering the tablets on individual slats and thereby controlling the count more accurately. Aylward's U.S. Pat. No. 6,185,901, which is incorporated herein by reference, discloses an apparatus that picks up individual tablets and delivers individual tablets in one direction to the container and is thereby able to count each tablet individually.
All of these methods rely on the bottle being moved into position under the discharge chute. The bottle is stopped and held stationary, while the tablets are delivered individually. The slats are stopped once the count is reached; the filled bottles are then released, and empty bottles are moved into place as the cycle is repeated. Each method's throughput is dependent on the length of the screw and the number of tablets per container. Generally, the bottle count per minute does not exceed 400 bottles per minute.
The above methods have several characteristics that limit their utility. The slats move in only one direction, and the tablets are counted one at a time and are not inspected while counting. Also, all of the above methods utilize intermittent linear motion of the containers as opposed to continuous rotary motion.